Wednesday, July 25, 2012

Bomb squad


 In our gorgeous, biodiverse, and blessed land where so many fine people seem to be passionate about possessing, "bearing" or otherwise abusing firearms, I have an excellent substitution for them. Somewhere in The Essential Earthman, Henry Mitchell translates bombyciferum (in reference to the Dolly Parton of mulleins) as "carrying a bomb": there is certainly something incendiary, outrageous and explosive about verbascums. Not a few are bona fide (albeit lovely in a fashion) weeds. Many if not most are massive and create problems with disposing of their bodies (like the year I grew two or three hundred: where to dump so many almost human sized corpses?) (P.S. you should click on the picture above to get a PROPER view of my harem early in late May)...

So what better way to indulge your slightly sociopathic urges, (if not altogether psychopathic) than to grow verbascums? That must explain my passion for these wooly monsters: I have grown dozens of species in my day. There are hundreds and hundreds of them--mostly concentrated in Greece and Turkey (interesting fact that). They are ridiculously variable as a genus: tiny little Verbascum acaule is a Greek alpine only a few inches tall and broad. And they can come in velvety purple and nearly pink flower color as well as startling white.


 But this is everyone's favorite (including mine): Verbascum bombyciferum really means "bearing wool", and the young leaves and especially the flower stalks are wonderfully velvety wooly white. It apparently is largely restricted to the Bithynian Olympus (nowadays called Ulu Dag) not far from Proussa (nowadays Bursa), a few hour's drive south of Constantinople (yes, I know: Istanbul). I had distant ancestors who hailed from these regions, and used the Greek names, and a touch of sentimentality suggests to me that they might have stumbled upon this in their Ionian wanderings. The flowers are much bigger than this picture suggests: two inches or so across, and they are abuzz with bees in the morning.


The first picture in this series was taken almost two months ago: look how they have grown! and continue blooming and blooming: there are many reasons to be grateful of having a large garden, and for me chief among these is that I can have verbascums self sow liberally and not have to worry too much about it. I do weed out many of the rosettes (hundreds of carcases eventually get depressing to remove and stash)...but I leave plenty for the amusement of my guests (and of myself)...



They are lovely any time of day, but in the early morning, when they postively glow in the dawn light, I am transfixed as I wander through my miniforest of wooly towers, like an oversized bee.

I have had sputtering nativists scold me for my love of mullein. I smile and commend their commitment to a noble cause (I love my natives too: monogamy is well and good for mere humans, but we plant Gods want a sizeable harem of our vegetable goddesses). "My vegetable love shall grow/vaster than empires and more slow" says Andrew Marvell. Genghis Khan has 600 human wives, after all: will you begrudge me my 6000 chlorophilic concubines?

This Olympic Mullein inspires hyperbole and endless love (from some of us). I have lots of seed to spare, b.t.w. (although often including hybrids with the dozen or so other species I also grow in my garden--sharp eyes should have picked one up in this last picture).

Now if we can only get the N.R.A. to cotton on to mulleins...

Sunday, July 22, 2012

Forever foxgloves!


 If I could pick one genus of shade loving plants I would not want to live without, I would pick the foxgloves without a second thought. Thanks to Darrell Probst, Epimediums are far more numerous and variable (I'm tempted by these, I admit), Primula is fabulous, but most species of primrose need far too much irrigation to be practical for most people. Hellebores are terrific, but the flowers (except, of course, for H. niger) for all their improvement are still a trifle glum for my taste.

 Ironically, the only foxglove commonly grown in "conventional" Denver gardens is D. purpurea, which is the least satisfactory in my opinion. It needs far more water than the other species to do well, and it is one of the few that is biennial. The one above came to me as Digitalis fontanesii, which has been lumped with D. grandiflora: the latter has a large range, and I suspect this is a regional variant--both are worth growing! [I stick to the old name because I see distinctions that evade the weary eyes of botanists poring over dried husks of plants]...


 Here is more typical D. grandiflora, growing at Denver Botanic Gardens: much taller, with less vividly colored flowers and a stricter habit. I have grown this plant for decades, and never tire of its crisp, proud display of subtle color. It takes a lot of sun, but I find it looks best in at least half days shade in Colorado.


This is one of the many hybrids that have popped up over the years at our various gardens: this one at Plantasia at DBG: probably grandiflora crossed with ferruginea (see below), but I could be wrong. Alas, hybrids are almost always sterile!


My current favorite (probably because it is the one I have obtained most recently), Digitalis parviflora may have "parvi-" "floras", but they are bunched so charmingly, and the honey-amber-caramel coloration is irresistible. I believe I have seen this in quite a dark chocolate brown--a form I would love to grow as well.

Alas, my best pictures of this are still on transparencies: this has been ridiculously lumped with the common, tall Digitalis purpurea (supposedly as "var. purpurea") to which I say "pshaw!": this is utterly distinct from the giant biennial: it makes a much hairier, trim rosette, and produces distinctively shaped, wonderfully flared trumpets over a very long season--these can be deep, crushed raspberry red. It is a pretty long lived perennial (I have kept them five or six years), and loves dry shade. It superficially resembles the better known D. thapsi: I grow the two nearby one another and they are very different indeed.

This has been one of the highlights of this year: I finally have gotten Digitalis heywoodii ("D. purpurea var. heywoodii" according to the botanists.) Imagine a compact common foxglove, only with wonderfully gray foliage and crystalline white flowers....only it's perennial!


I finish with Digitalis ferruginea, another bronzy species that can tower to six or more feet tall. It thrives in a variety of sites and soils, and though the individual plants can be monocarpic, they invariably self sow and persist like sound perennials. The pale primrose color in the background is yet another foxglove, in this case Digitalis lutea, one of the smaller flowered sorts. But all indispensible...

And there are many more I have not discussed. All of these have settled down in my home garden to many niches. Did I mention that they make outstanding cut flowers? Easily grown from seed, and some can even be divided. They are tough and carefree and persist year in year out, blooming for months at a time, and looking clean and attractive even out of bloom. Each year my garden seems to have a few more patches of  them.....but never quite enough!

Wednesday, July 18, 2012

Woodland wonders this time...


I know it's garish and brash and really in awful taste, but Hosta 'Patriot' does make a statement: all the more so because there were a bevy of these planted--all looking splendidly healthy--along Denver's longest and least attractive street (Colfax) not far from Denver Botanic Gardens...


This is all preamble to say how much I enjoy shade plants generally, especially in this beastly hot summer when my poor summer alpines are being cooked and even the cacti are scorched. A closeup of 'Patriot' (I am almost tempted to buy and plant one in my own shade garden)...almost is the operative word....


THIS is more like it: a terrible picture (I took a good one, but how to find it?) of one of my favorite "new" finds: Dan Johnson has had this for years in his home garden, and gave a giant clump to the Gardens where it completely befuddled the Ratzeputz Gang (only a half dozen of the world's greatest perennial experts) and me too. I eventually tracked down the name...Napaea dioica has a whole list of pluses: first of all it is monotypic (monotypical plants always get brownie points). It is obscure and restricted in range--in this case to the central Midwest. Hardly known in commerce. And it is wonderfully statuesque and easily grown in shady gardens: what more can you want? Oh yes, and in the Mallow family. Looking great this summer at Denver Botanic Gardens (and a little one at my home garden!). Oh yes, it has a cool name that's fun to pronounce (and it's dioecious: more brownie points!)


A bevy of Lilium conocolor in the Plantasia Garden at DBG: these miniature lilies are hard to fit in most gardens: why not plant a mass and have a spectacle for a day or two...a mini spectacle, that delights perhas three people...what a luxury to have 25 acres where we can perform this sort of mini miracle...

Meanwhile, I shall retire to the shade among the foxgloves and ferns, the towering Ligularias and corydalis and hunker down for another blazing day! G'day!

Sunday, July 15, 2012

Midsummer wonders...


 It seems as though everyone (except Seattleites) has had an incredibly hot summer thus far. Last weekend we received 3" of truly blessed rain, otherwise I can't imagine how frustrated we would be by now. The vast throngs of gems that bloom from early spring to early summer are now mostly in seed (or long past seed) and I am busy cutting things back and removing debris. But there are still a few gems that brighten the garden and lift our spirits...I highly recommend all of them for your garden as well. The first is the only truly hardy form of Campanula fragilis, var. cavalinii, which I believe first came from a Holubec collection from Italy. Campanulas truly are the backbone of summer rock gardens.

It is ironic that the West which boasts dozens of stunning buckwheats is utterly trumped in the garden right now with this glowing mound of gold from West Virginia's shale barrens. Eriogonum allenii is one of the toughest, longest blooming and most rewarding perennials I know. I am amazed it is so little seen in gardens, considering Jelitto Seed company has been selling it for years.


Most any form of Escobaria vivipara is precious, but var. bisbeeana had flowers 3 inches across, I kid you not. This may have only bloomed two days, but more than made up in spectacle what it lacked in duration.

Such an unphotogenic plant. But I shall never be without Helichrysum plicatum: this is the most durable, long lived and adaptable of this immense genus. Hailing from the Mediterranean, it is also very drought tolerant. The flowers last for nearly a month, and even the seedheads are decorative afterwards. It exudes a heavenly fragrance somewhere between spice cake and curry sauce.


I have rhapsodized about Ziziphora somewhere before. The pale blue powderpuffs last much of the summer, and the aroma of bruised foliage is heavenly. I am not sure which species this is (a photograph from the Rock Alpine Garden): it looks very much like pamiroalaica or forms of clinopodioides we have grown in the past. Plants similar to this grew everywhere in the Altai and the Tian Shan: they should be growing in all our gardens as well (just think Thyme on Steroids)


And of course, oreganos. Here is one similar to O. scabrum performing marvellously on Sandy Snyder's enchanting crevice garden. We may have had desert heat for a month, but her garden is fresh and colorful and rewarding.

Although we could do with another good soaking rain!

Friday, July 13, 2012

Salvia mundi redux: The Salvia canescens complex.


Does the world really need another salvia? I featured a closeup of Salvia phlomoides from Morocco (collected by Mike Kintgen, and photographed in his garden this spring) earlier this spring and I think you will agree this deserves a second view. There is an astonishing website that features closeups and glamour shots of literally hundreds of salvias (interestingly enough, this one is not included!). What is intriguing to me is the variability that is found within a single species and within a section of a genus like this...incidentally, this Western Mediterranean species has a cousin found in Turkey, Salvia hypargeia (below) has lax rosettes of narrower, leaves, not quite so silvery, and much taller wands with these wonderful lavender blooms--altogether different in the garden, but morphologically quite close: indeed, they cross readily!


And then, of course, the only one of this complex that is widely available in commerce is Salvia daghestanica (or Salvia canescens var. daghestanica), first introduced to horticulture by Henrik Zetterlund of Gothenburg Botanical Garden in Sweden, collected on an expedition to the Caucasus of Russia in the 1980's. This has been an alpine house treasure in Britain for decades, but in the warm, dry climate of the Rockies, it has become a glamorous and indispensible groundcover, marketed by the Plant Select program. If you click on that link you will find yet another account of this species, which rates very high indeed in my personal hierarchy of botanical beauty (a highly eclectic scale, I admit).

Below you can see on of the many huge stands of this at the Gardens at Kendrick Lake where it seems very much at home. Someone at Plant Select (perhaps it was even me) came up with the "common" name platinum sage for this. I have been ribbed about this on occasion--people must have their common names, you know--and if the plant is actually almost non-existent in the trade and exotic in its origins, how on earth do you come up with a vernacular name? You make it up, that's how. And although I don't recall ever seeing wild platinum in mineral form, I don't suppose many others have either: so let's just pretend it looks like these wonderfully silvery leaves, Okay? Get over it already!

 This shows the whole shebang--probably six or more feet across. It is as much a picture out of bloom with those platinum leaves, after all! Now contrast this with Salvia hypargeia below:


By contrast, the much more diffuse Salvia hypargeia is positively green leaved.  This Grex includes yet another taxon, Salvia canescens var. canescens, which grows further eastward in Asia, as far as the Himalayas. It has established a toe-hold in cultivation (with one delightful tuft in my home garden): I am sorry that I do not have it to add to this complex of pictures. It is yet another variation on a theme. Although these are close enough to hybridize, they are each worth including in a garden (in my garden). A bit of history may be of interest.

I believe all the Salvia daghestanica in cultivation in America derive from a few cuttings I brought back in 1991 from Jack Elliot's alpine house. Plant Select has now made this almost a commonplace! Salvia hypargeia was first grown at Denver Botanic Gardens from seed collected by Jim Archibald, but by a decade ago we had almost lost this to our collection (and likely cultivation). Fortunately, Mike Kintgen took an interest in the latter and blew the numbers up dramatically in his home garden, reintroducing it to the Rock Alpine Garden. Salvia phlomoides was first found by Rod Haenni in Morocco, but collected by Mike Kintgen, who also grew the first plants and has distributed seed to specialty nurseries, so this is now become a plant many of us in the Front Range can enjoy.

Thomas Jefferson would have approved of our work with these salvias. After all,he declared that "the greatest service which can be rendered any country is to add an useful plant to it's culture".

Monday, July 9, 2012

God's flowers: the underappreciated pinks!


Technically I suppose these are "Zeus' flowers", since "Di-" must be the genetive plu-perfect subjunctive aorist of Zeus somehow in Ancient Greek (don't take my grammar too literally by the way)--and since Zeus was born on the Dictyan peninsula (as was my grandfather) it makes perfect sense that I am daft for pinks.

My first picture is a patch of one of innumerable hybrid Dianthus groups allied to the "Floral Lace Mix" (Dianthus x allwoodii "alpinus"), involving Dianthus chinensis, D. barbatus and probably D. alpinus. These are anathema to alpine purists, but I have to say that few plants have provided more color in my garden for longer this year than a vigorous patch of these I planted several years ago. These are usually grown as annuals, however, they have proved quite perennial in this one spot, and (letting my plantsman's guard down a tad..) I have to say that they are hard to beat!


This is much more along the lines that purists would demand: I believe this may be Dianthus erinaceus, but in an extremely vigorous and perennial form. It is almost as compact as the notoriously dense and unreliably flowered Dianthus anatolicus (mistakenly sold under other names)...but this one is easily propagated from cuttings, and sets copious seed and improves from year to year. What's not to love?


I obtained this as Dianthus brevicaulis, although I have something listed as a form of D. haematocalyx (see below). It was collected in Turkey, and has been a spectacular new cushion plant that thrives in the rock garden or in troughs, has been long lived and makes a wonderful silvery mound. What more can you want?

Perhaps you want yellow? I once saw a yellow Dianthus wild in South Africa, but Dianthus knappii  is always yellow and which is actually quite commonly available and strangely absent from gardens. The literature bad mouths this plant, saying it is floppy and has too long of stems: grown hard as it was here at the Rock Alpine Garden it is utterly delightful, blooming all of June. I find this thrives in a variety of soils and exposures, tolerating abundant water and quite dry conditions. I would not want to be without it!

Dianthus giganteus can grow four or more feet tall: here it is a mere three or so in my totally unwatered xeriscape. At my girlfriend's house it has self sown throughout her dry border, and makes a wonderful spectacle on and off all summer. This makes a great cut flower, and surely is one of the toughest of the genus. I have come to love it more: yes it is gangly, but who cares! It is perfect as a see through plant in a border, and should be better known and grown. I believe it comes from Crete: this may have been the one Zeus fell in love with, come to think of it!



This form of Dianthus haematocalyx var. pindicola is also growing in an unwatered garden. The flowers persist for only a few weeks, but they are dazzling while they are out. Another winner...


I finish with Dianthus petraeus ssp. noeanus, which I first obtained (like so many treasures I love) from Bob Putnam, a great nurseryman who ran a rock garden nursery in the Seattle area in the 1970s and 80's. He insisted I take some pots of these, and the very same plants he gave me over thirty years ago are still thriving and wafting their incredibly rich, almost tropical fragrance every evening for weeks and weeks on end in the summer months. This is in full bloom for me now several places in my garden...

These are just a handful of virtually unknown and terribly underappreciated pinks: no genus is more forgiving, more easily grown for seed and few have such heavenly scented flowers. And most are incredibly heat and drought tolerant.

It's time to give God's flowers their due!

Thursday, July 5, 2012

Childsplay...DBG's stunning annex


If someone had told me years ago that Denver Botanic Gardens would have created about an acre of scree on top of a garage roof and filled it with floriferous gems, I would have surely have never believed it possible. And now, entering its third growing season, the Children's Garden at Denver Botanic Gardens has gone from strength to strength: It is amazing how little tiny pots of alpines have spread a foot, two feet--even three or more feet across in just a few years. Of course, they are growing in an amazing medium consisting of expanded shale with special amendments and micronutrients: all the plants seem to love it...behold not just ice plants above, but big mounds of crucifers (Alyssum, I believe) and the white mass in the back I will speak about at the end: the garden consists of hundreds if not thousands of perfect mounds and mats, each of which would take a prize in a British flower show!

Although many of the plants growing here are rather choice, there are workhorses like Penstemon pinifolius, which never looked or grew better anywhere. various thymes and veronicas provide wonderful lavender and blue counterpoints to the incredibly flashy penstemons throughout--these are the most amazing demonstration to me of the importance of drainage and dry crowns: the penstemons here come back year after year lustily...


One of my very few quibbles in Jim Locklear's masterful new monograph on Phlox is that he lumps this extremely distinctive Arizona native into the widepsread Phlox longifolia: I think Phlox grayi will prove to be distinct enough to retain its identity: it is almost as compact as a creeping phlox, but it thrives in a wider range of soils and irrigation regimens including extremely dry. It has the wonderful habit of reblooming in late summer. There are vast scatterrugs of this rare phlox throughout this garden.

There was a time when I yearned to grow the high altitude, winter hardy sun daisies from South Africa (Osteospermum). Plant Select has introduced three clones thus far, and I have quite a few seedlings (some intermediate) in my home garden, but I must admit this paperwhite, blindingly white groundcover that was obtained as cuttings from Fritz Kummert in Austria takes the cake. It is uutterly resistant to the various soil pathogens that cause the other clones to die back suddenly. There are numerous clumps of this wonderful plant throughout this garden--they bloom for months in spring, and rebloom throughout the summer and fall. I have seen and admired 'Avalancche' in many a garden, but none can begin to compare to the ones in Children's Garden in size or vigor.

Ross Shrigley was the Gardens' staff member who first designed and planted the garden. He quit to work for Fort Collins Nursery Wholesale over a year ago, and Julie Casault has ably carried on the management of this amazing garden. There are dozens of taxa which thrive here and have been challenging, short lived or impossible at York Street proper: so next time you visit the Gardens, make sure you go visit the Chldren's garden across the street: it's not just for kids...believe me!

Wednesday, July 4, 2012

An All American treasure for the 4th of July...woo hooo!


Truth in advertising: the picture was taken a few weeks ago. I find it hard to believe I haven't blogged about this little morsel yet: Escobaria sneedii var. leei (or just plain Escobaria leei for some of us) rates off the charts on the cuteness scale (a scientific measurement of plant adorability invented by Pat Hayward several decades ago). This plant is unique and notable for a whole suite of reasons:

            1) It is one of the easiest cacti to grow
            2) It is hardy almost anywhere (provided it has drainage, of course, and lots of sun): I know it is being grown all over southern Canada, the Northeastern and midwestern USA and all across this great country of ours (it is Fourth of July after all today)...not to mention Europe.
            3) It propagates like a schmoo (if you do not know what a schmoo is I feel sorry for you).
            4) It is listed as Threatened on the Federal Endangered list (only a few thousand individuals are known in its limited range inside Carlsbad Caverns National Park)...I am sure more plants of this are growing in Denver area gardens nowadays than in all the wild! And who knows how many in gardens around the world...a good example of why cultivating a plant probably aids in its conservation: no need to ever recollect this when it is so widely known and grown, and people now have a living reminder of how important preserving a wild plant must be.
            5) Yes, it has spines, but they are of the wimpiest kind: you could easily toss this back and forth and not hurt yourself nor your fellow tosser. A rather gruesome image, actually (do please propagate it when you are done tossing).


This is a clump at Denver Botanic Gardens last year: this was propagated from a piece of a plant that had been despoiled by a visitor (one of the very few plants ever to have been so vandalized): the central portion of a large clump had been pulled up, but the surrounding pieces remained: I decided to propagate these and put them all over the garden--this was perhaps fifteen, maybe 20 years ago. And they have gone on to spread and cluster....Interestingly enough, this was also one of the very few plants ever stolen at the Gardens on Kendrick Lake. Hey nurserymen friends: if people are stealing these little hummers, maybe that means you should propagate and sell them?

High Country Gardens sells this mail order (it's amazing more nurseries don't), and in the Denver area you can always find a large assortment of this at Timberline Gardens--Kelly Grummons has actually grown this from seed and selected an especially tiny form which he really needs to name--it is distinctive, and if possible, even cuter!

There are a few cacti that are even smaller in Mexico and South America. There are cacti with far more spectacular flowers. But I doubt that there are any that have so many stellar attributes at one time....I really think this is a cactus that anyone and everyone in America should know and grow. (P.S. it thrives on a windowsill--you don't even have to grow it in a succulent trough. But shouldn't everyone have a few troughs full of hardy succulents?)...

I have proposed this several times to the Plant Select committee, and I am always rebuffed ("too small", "too weird", "too esoteric", "too different"). I think they are dead wrong, don't you?